Re: NILFS2 on an Intel X25-M SSD

["Carlos R. Mafra" <crmafra-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Am 30.12.2009 19:46, schrieb Ryusuke Konishi:
> On Tue, 29 Dec 2009 20:48:47 +0100, "Carlos R. Mafra" wrote:
>> Is there any specific tweak in NILFS2 to use with an SSD? Would you
>> reccomend using NILFS2 on a SSD right now?
>>
>> Is the issue mentioned here
>>
>> https://www.nilfs.org/pipermail/users/2009-March/000514.html
>>
>> about excessive writing in the GC already fixed?
>> That is the most pressing fear I have about NILFS2 for the SSD.
> 
> Not yet, sorry.  I'm working on some performance optimization for high
> speed drives espacially for SSD.  Revising GC is another priority, but
> it would need some time.
> 
> The massive I/O by the current garbage collector may shorten the life
> of SSD.  So, I don't recommend yet.

Hmm, then I won't use NILFS2 on the SSD for now.

I am testing it in an external HD for the last two days to get a feeling,
and so far everything looks good and stable. It is a pity that the 
massive I/O problem kind of prevents putting it on the SSD.

Naively I would think that the GC will always create some I/O that
other filesystems don't have, by its very definition. Can you
quantify by how much the current GC is writing in excess and what would
be the acceptable numbers?

> If you are not interested in snapshots, I think nilfs is not always a
> good choice because high-end SSD drives are already doing lfs like
> optimization internally.  Intel SSD exactly looks like this sort of
> drives though I'm using nilfs on X25-M and X25-E ;)

The log-structured nature of the file system seemed a good thing for
the health of the SSD, yes. But the snapshot feature is something
interesting to have too and I was willing to have it :-)